1. Field of the Invention
The present invention relates to systems and apparatus that facilitate a precise process by which a batch-type process may achieve the efficiency of a continuous process, reducing the net fluid volume deficiency in a patient during a medical treatment process where fluid must be removed from a patient.
2. Description of the Prior Art
Growth in technology has allowed the medical profession to measure the precise natural fluid ratios found in the human body. Consequently, preserving these ratios during medical treatments is desirable, particularity in treatments such as photophoresis, which is discussed and claimed in U.S. Pat. No. 5,984,887 and U.S. application Ser. No. 08/832,219, which are expressly incorporated herein by reference. By way of example, a photophoresis process such as the UVAR(copyright) process (Therakos, Inc., West Chester, Pa.) removes blood from a patient, separates the buffy coat from the plasma and red blood cells and replaces the biological fluids in a batch process. When blood is removed from the patient, however, a volume deficit is created within the patient. This volume deficit is particularly detrimental in small children and the elderly or in patients that suffer from certain illnesses or diseases because their blood has a higher percentage of plasma relative to the cellular components. This volume imbalance requires that a greater volume of blood be drawn from the patient to obtain the required amount of red blood cells. This especially impacts infants and sick children who may have low body weight and hemocrit percentages of 25-30% which is significantly lower than the normal average of 45%. The need thus arose to be able to detect small incremental changes in natural fluid ratios within the body and to use these measurements to create a process by which the net fluid volume collected or removed from a patient may be reduced during-a medical treatment process.
The objects of the present invention include providing systems and apparatus for increasing the efficiency of a continuous process through a modified batch-type process, using a biological fluid and one or more centrifuge bowls to reduce the net fluid volume deficiency in a patient during a medical treatment process. An additional object may be to alleviate the difficulty in finding multiple proper insertion sites by requiring only one insertion site.
The present invention solves the inadequacies of the prior art by being able to detect small incremental changes in fluid volumes and by achieving the results of a continuous process. An efficient batch process or other Latham bowl batch-type technique is used to simulate a continuous process by which fluid is continually added and removed from a patient to account for any net fluid volume deficiency at any point in time within a medical treatment process and yet achieve higher separation and treatment efficiencies than, for example, a continuous flow separation treatment.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the present invention may include, in one or more embodiments, a method, apparatus, and system, and in a preferred embodiment an automated system, for reducing the net fluid volume change of a biological fluid within a patient during a treatment cycle by determining the net fluid volume change in the patient, adjusting the net fluid volume deficiency in the patient to obtain a minimal net fluid volume deficiency, and maintaining a minimal net fluid volume deficiency.
Additionally, determining the net fluid volume deficiency may be achieved through the use of a load cell, designed to measure the change in weight of a storage chamber. Adjusting the net fluid volume deficiency to obtain a minimal net fluid volume deficiency may involve increasing or decreasing the amount of biological fluid returned to a patient through use of a valving means and/or a pumping means to adjust the flow of a biological fluid. Maintaining the net fluid volume deficiency may also involve using one or more of the following: a load cell, pumping means, and valving means. Maintaining a minimal net fluid volume deficiency may also involve monitoring the net fluid volume deficiency.
The automation of the system may be accomplished by a computer system. Such a system may comprise a computer processor with memory which is coupled to the computer processor, and a computer process that is stored in the memory that includes obtainers and controllers configured to obtain, adjust and maintain a minimal net fluid volume deficiency. The obtainer may be associated with a load cell and the controllers may be associated with valving means and/or pumping means designed to adjust the minimum net fluid volume deficiency. The pumping means may be designed to increase or decrease the flow of biological fluids to be delivered to a patient.
Alternatively, the system for determining, adjusting, and maintaining the minimal net fluid volume deficiency may be a controller that communicates with the load cell, valving means, and pumping means. This controller may be a computer that controls the load cell, valving means, and pumping means.
In an alternative embodiment, the biological fluid may be primer fluid. Preferably, the primer fluid may contain red blood cells, plasma, or red blood cells and plasma.
It is understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. The accompanying drawings illustrate several embodiments of the invention and together with the description serve to explain the principles of the invention.